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5f677af2da
into a UNION that has some type coercions applied to the component queries, so long as the qual itself does not reference any columns that have such coercions. Per example from Jonathan Bartlett 24-Apr-03.
1046 lines
30 KiB
C
1046 lines
30 KiB
C
/*-------------------------------------------------------------------------
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*
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* prepunion.c
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* Routines to plan set-operation queries. The filename is a leftover
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* from a time when only UNIONs were implemented.
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*
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* There is also some code here to support planning of queries that use
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* inheritance (SELECT FROM foo*). This no longer has much connection
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* to the processing of UNION queries, but it's still here.
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*
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*
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* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.93 2003/04/24 23:43:09 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "catalog/pg_type.h"
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#include "nodes/makefuncs.h"
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#include "optimizer/clauses.h"
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#include "optimizer/plancat.h"
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#include "optimizer/planmain.h"
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#include "optimizer/planner.h"
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#include "optimizer/prep.h"
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#include "optimizer/tlist.h"
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#include "parser/parse_clause.h"
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#include "parser/parse_coerce.h"
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#include "parser/parsetree.h"
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#include "utils/lsyscache.h"
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typedef struct
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{
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Index old_rt_index;
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Index new_rt_index;
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Oid old_relid;
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Oid new_relid;
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} adjust_inherited_attrs_context;
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static Plan *recurse_set_operations(Node *setOp, Query *parse,
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List *colTypes, bool junkOK,
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int flag, List *refnames_tlist);
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static Plan *generate_union_plan(SetOperationStmt *op, Query *parse,
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List *refnames_tlist);
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static Plan *generate_nonunion_plan(SetOperationStmt *op, Query *parse,
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List *refnames_tlist);
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static List *recurse_union_children(Node *setOp, Query *parse,
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SetOperationStmt *top_union,
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List *refnames_tlist);
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static List *generate_setop_tlist(List *colTypes, int flag,
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bool hack_constants,
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List *input_tlist,
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List *refnames_tlist);
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static List *generate_append_tlist(List *colTypes, bool flag,
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List *input_plans,
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List *refnames_tlist);
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static bool tlist_same_datatypes(List *tlist, List *colTypes, bool junkOK);
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static Node *adjust_inherited_attrs_mutator(Node *node,
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adjust_inherited_attrs_context *context);
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static Relids adjust_relid_set(Relids relids, Index oldrelid, Index newrelid);
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static List *adjust_inherited_tlist(List *tlist, Oid new_relid);
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/*
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* plan_set_operations
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*
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* Plans the queries for a tree of set operations (UNION/INTERSECT/EXCEPT)
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*
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* This routine only deals with the setOperations tree of the given query.
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* Any top-level ORDER BY requested in parse->sortClause will be added
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* when we return to grouping_planner.
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*/
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Plan *
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plan_set_operations(Query *parse)
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{
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SetOperationStmt *topop = (SetOperationStmt *) parse->setOperations;
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Node *node;
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Query *leftmostQuery;
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Assert(topop && IsA(topop, SetOperationStmt));
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/*
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* Find the leftmost component Query. We need to use its column names
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* for all generated tlists (else SELECT INTO won't work right).
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*/
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node = topop->larg;
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while (node && IsA(node, SetOperationStmt))
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node = ((SetOperationStmt *) node)->larg;
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Assert(node && IsA(node, RangeTblRef));
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leftmostQuery = rt_fetch(((RangeTblRef *) node)->rtindex,
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parse->rtable)->subquery;
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Assert(leftmostQuery != NULL);
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/*
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* Recurse on setOperations tree to generate plans for set ops. The
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* final output plan should have just the column types shown as the
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* output from the top-level node, plus possibly a resjunk working
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* column (we can rely on upper-level nodes to deal with that).
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*/
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return recurse_set_operations((Node *) topop, parse,
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topop->colTypes, true, -1,
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leftmostQuery->targetList);
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}
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/*
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* recurse_set_operations
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* Recursively handle one step in a tree of set operations
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*
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* colTypes: list of type OIDs of expected output columns
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* junkOK: if true, child resjunk columns may be left in the result
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* flag: if >= 0, add a resjunk output column indicating value of flag
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* refnames_tlist: targetlist to take column names from
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*/
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static Plan *
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recurse_set_operations(Node *setOp, Query *parse,
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List *colTypes, bool junkOK,
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int flag, List *refnames_tlist)
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{
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if (IsA(setOp, RangeTblRef))
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{
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RangeTblRef *rtr = (RangeTblRef *) setOp;
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RangeTblEntry *rte = rt_fetch(rtr->rtindex, parse->rtable);
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Query *subquery = rte->subquery;
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Plan *subplan,
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*plan;
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Assert(subquery != NULL);
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/*
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* Generate plan for primitive subquery
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*/
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subplan = subquery_planner(subquery, 0.0 /* default case */ );
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/*
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* Add a SubqueryScan with the caller-requested targetlist
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*/
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plan = (Plan *)
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make_subqueryscan(generate_setop_tlist(colTypes, flag, true,
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subplan->targetlist,
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refnames_tlist),
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NIL,
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rtr->rtindex,
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subplan);
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return plan;
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}
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else if (IsA(setOp, SetOperationStmt))
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{
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SetOperationStmt *op = (SetOperationStmt *) setOp;
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Plan *plan;
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/* UNIONs are much different from INTERSECT/EXCEPT */
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if (op->op == SETOP_UNION)
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plan = generate_union_plan(op, parse, refnames_tlist);
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else
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plan = generate_nonunion_plan(op, parse, refnames_tlist);
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/*
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* If necessary, add a Result node to project the caller-requested
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* output columns.
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*
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* XXX you don't really want to know about this: setrefs.c will apply
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* replace_vars_with_subplan_refs() to the Result node's tlist.
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* This would fail if the Vars generated by generate_setop_tlist()
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* were not exactly equal() to the corresponding tlist entries of
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* the subplan. However, since the subplan was generated by
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* generate_union_plan() or generate_nonunion_plan(), and hence
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* its tlist was generated by generate_append_tlist(), this will
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* work.
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*/
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if (flag >= 0 ||
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!tlist_same_datatypes(plan->targetlist, colTypes, junkOK))
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{
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plan = (Plan *)
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make_result(generate_setop_tlist(colTypes, flag, false,
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plan->targetlist,
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refnames_tlist),
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NULL,
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plan);
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}
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return plan;
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}
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else
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{
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elog(ERROR, "recurse_set_operations: unexpected node %d",
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(int) nodeTag(setOp));
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return NULL; /* keep compiler quiet */
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}
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}
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/*
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* Generate plan for a UNION or UNION ALL node
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*/
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static Plan *
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generate_union_plan(SetOperationStmt *op, Query *parse,
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List *refnames_tlist)
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{
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List *planlist;
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List *tlist;
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Plan *plan;
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/*
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* If any of my children are identical UNION nodes (same op, all-flag,
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* and colTypes) then they can be merged into this node so that we
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* generate only one Append and Sort for the lot. Recurse to find
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* such nodes and compute their children's plans.
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*/
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planlist = nconc(recurse_union_children(op->larg, parse,
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op, refnames_tlist),
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recurse_union_children(op->rarg, parse,
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op, refnames_tlist));
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/*
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* Generate tlist for Append plan node.
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*
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* The tlist for an Append plan isn't important as far as the Append is
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* concerned, but we must make it look real anyway for the benefit of
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* the next plan level up.
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*/
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tlist = generate_append_tlist(op->colTypes, false,
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planlist, refnames_tlist);
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/*
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* Append the child results together.
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*/
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plan = (Plan *) make_append(planlist, false, tlist);
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/*
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* For UNION ALL, we just need the Append plan. For UNION, need to
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* add Sort and Unique nodes to produce unique output.
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*/
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if (!op->all)
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{
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List *sortList;
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tlist = new_unsorted_tlist(tlist);
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sortList = addAllTargetsToSortList(NIL, tlist);
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plan = (Plan *) make_sort_from_sortclauses(parse, tlist,
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plan, sortList);
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plan = (Plan *) make_unique(tlist, plan, sortList);
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}
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return plan;
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}
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/*
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* Generate plan for an INTERSECT, INTERSECT ALL, EXCEPT, or EXCEPT ALL node
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*/
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static Plan *
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generate_nonunion_plan(SetOperationStmt *op, Query *parse,
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List *refnames_tlist)
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{
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Plan *lplan,
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*rplan,
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*plan;
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List *tlist,
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*sortList,
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*planlist;
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SetOpCmd cmd;
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/* Recurse on children, ensuring their outputs are marked */
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lplan = recurse_set_operations(op->larg, parse,
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op->colTypes, false, 0,
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refnames_tlist);
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rplan = recurse_set_operations(op->rarg, parse,
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op->colTypes, false, 1,
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refnames_tlist);
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planlist = makeList2(lplan, rplan);
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/*
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* Generate tlist for Append plan node.
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*
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* The tlist for an Append plan isn't important as far as the Append is
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* concerned, but we must make it look real anyway for the benefit of
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* the next plan level up. In fact, it has to be real enough that the
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* flag column is shown as a variable not a constant, else setrefs.c
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* will get confused.
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*/
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tlist = generate_append_tlist(op->colTypes, true,
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planlist, refnames_tlist);
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/*
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* Append the child results together.
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*/
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plan = (Plan *) make_append(planlist, false, tlist);
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/*
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* Sort the child results, then add a SetOp plan node to generate the
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* correct output.
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*/
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tlist = new_unsorted_tlist(tlist);
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sortList = addAllTargetsToSortList(NIL, tlist);
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plan = (Plan *) make_sort_from_sortclauses(parse, tlist, plan, sortList);
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switch (op->op)
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{
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case SETOP_INTERSECT:
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cmd = op->all ? SETOPCMD_INTERSECT_ALL : SETOPCMD_INTERSECT;
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break;
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case SETOP_EXCEPT:
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cmd = op->all ? SETOPCMD_EXCEPT_ALL : SETOPCMD_EXCEPT;
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break;
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default:
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elog(ERROR, "generate_nonunion_plan: bogus operation code");
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cmd = SETOPCMD_INTERSECT; /* keep compiler quiet */
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break;
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}
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plan = (Plan *) make_setop(cmd, tlist, plan, sortList,
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length(op->colTypes) + 1);
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return plan;
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}
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/*
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* Pull up children of a UNION node that are identically-propertied UNIONs.
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*
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* NOTE: we can also pull a UNION ALL up into a UNION, since the distinct
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* output rows will be lost anyway.
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*/
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static List *
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recurse_union_children(Node *setOp, Query *parse,
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SetOperationStmt *top_union,
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List *refnames_tlist)
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{
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if (IsA(setOp, SetOperationStmt))
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{
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SetOperationStmt *op = (SetOperationStmt *) setOp;
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if (op->op == top_union->op &&
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(op->all == top_union->all || op->all) &&
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equalo(op->colTypes, top_union->colTypes))
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{
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/* Same UNION, so fold children into parent's subplan list */
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return nconc(recurse_union_children(op->larg, parse,
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top_union,
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refnames_tlist),
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recurse_union_children(op->rarg, parse,
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top_union,
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refnames_tlist));
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}
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}
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/*
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* Not same, so plan this child separately.
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*
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* Note we disallow any resjunk columns in child results. This is
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* necessary since the Append node that implements the union won't do
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* any projection, and upper levels will get confused if some of our
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* output tuples have junk and some don't. This case only arises when
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* we have an EXCEPT or INTERSECT as child, else there won't be
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* resjunk anyway.
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*/
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return makeList1(recurse_set_operations(setOp, parse,
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top_union->colTypes, false,
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-1, refnames_tlist));
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}
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/*
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* Generate targetlist for a set-operation plan node
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*
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* colTypes: column datatypes for non-junk columns
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* flag: -1 if no flag column needed, 0 or 1 to create a const flag column
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* hack_constants: true to copy up constants (see comments in code)
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* input_tlist: targetlist of this node's input node
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* refnames_tlist: targetlist to take column names from
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*/
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static List *
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generate_setop_tlist(List *colTypes, int flag,
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bool hack_constants,
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List *input_tlist,
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List *refnames_tlist)
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{
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List *tlist = NIL;
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int resno = 1;
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List *i;
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Resdom *resdom;
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Node *expr;
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foreach(i, colTypes)
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{
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Oid colType = lfirsto(i);
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TargetEntry *inputtle = (TargetEntry *) lfirst(input_tlist);
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TargetEntry *reftle = (TargetEntry *) lfirst(refnames_tlist);
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int32 colTypmod;
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Assert(inputtle->resdom->resno == resno);
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Assert(reftle->resdom->resno == resno);
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Assert(!inputtle->resdom->resjunk);
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Assert(!reftle->resdom->resjunk);
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/*
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* Generate columns referencing input columns and having
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* appropriate data types and column names. Insert datatype
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* coercions where necessary.
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*
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* HACK: constants in the input's targetlist are copied up as-is
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* rather than being referenced as subquery outputs. This is
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* mainly to ensure that when we try to coerce them to the output
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* column's datatype, the right things happen for UNKNOWN
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* constants. But do this only at the first level of
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* subquery-scan plans; we don't want phony constants appearing in
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* the output tlists of upper-level nodes!
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*/
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if (hack_constants && inputtle->expr && IsA(inputtle->expr, Const))
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expr = (Node *) inputtle->expr;
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else
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expr = (Node *) makeVar(0,
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inputtle->resdom->resno,
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inputtle->resdom->restype,
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inputtle->resdom->restypmod,
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0);
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if (inputtle->resdom->restype == colType)
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{
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/* no coercion needed, and believe the input typmod */
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colTypmod = inputtle->resdom->restypmod;
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}
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else
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{
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expr = coerce_to_common_type(expr,
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colType,
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"UNION/INTERSECT/EXCEPT");
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colTypmod = -1;
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}
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resdom = makeResdom((AttrNumber) resno++,
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colType,
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colTypmod,
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pstrdup(reftle->resdom->resname),
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false);
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tlist = lappend(tlist, makeTargetEntry(resdom, (Expr *) expr));
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input_tlist = lnext(input_tlist);
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refnames_tlist = lnext(refnames_tlist);
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}
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if (flag >= 0)
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{
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/* Add a resjunk flag column */
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resdom = makeResdom((AttrNumber) resno++,
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INT4OID,
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-1,
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pstrdup("flag"),
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true);
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/* flag value is the given constant */
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expr = (Node *) makeConst(INT4OID,
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sizeof(int4),
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Int32GetDatum(flag),
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false,
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true);
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tlist = lappend(tlist, makeTargetEntry(resdom, (Expr *) expr));
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}
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return tlist;
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}
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|
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/*
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* Generate targetlist for a set-operation Append node
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*
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* colTypes: column datatypes for non-junk columns
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* flag: true to create a flag column copied up from subplans
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* input_plans: list of sub-plans of the Append
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* refnames_tlist: targetlist to take column names from
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*
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* The entries in the Append's targetlist should always be simple Vars;
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* we just have to make sure they have the right datatypes and typmods.
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*/
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static List *
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generate_append_tlist(List *colTypes, bool flag,
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List *input_plans,
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List *refnames_tlist)
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{
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List *tlist = NIL;
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int resno = 1;
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List *curColType;
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int colindex;
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Resdom *resdom;
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Node *expr;
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List *planl;
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int32 *colTypmods;
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/*
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* First extract typmods to use.
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*
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* If the inputs all agree on type and typmod of a particular column, use
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* that typmod; else use -1.
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*/
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colTypmods = (int32 *) palloc(length(colTypes) * sizeof(int32));
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foreach(planl, input_plans)
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{
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Plan *subplan = (Plan *) lfirst(planl);
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List *subtlist;
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curColType = colTypes;
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colindex = 0;
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foreach(subtlist, subplan->targetlist)
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{
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TargetEntry *subtle = (TargetEntry *) lfirst(subtlist);
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if (subtle->resdom->resjunk)
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continue;
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Assert(curColType != NIL);
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if (subtle->resdom->restype == lfirsto(curColType))
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{
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/* If first subplan, copy the typmod; else compare */
|
|
if (planl == input_plans)
|
|
colTypmods[colindex] = subtle->resdom->restypmod;
|
|
else if (subtle->resdom->restypmod != colTypmods[colindex])
|
|
colTypmods[colindex] = -1;
|
|
}
|
|
else
|
|
{
|
|
/* types disagree, so force typmod to -1 */
|
|
colTypmods[colindex] = -1;
|
|
}
|
|
curColType = lnext(curColType);
|
|
colindex++;
|
|
}
|
|
Assert(curColType == NIL);
|
|
}
|
|
|
|
/*
|
|
* Now we can build the tlist for the Append.
|
|
*/
|
|
colindex = 0;
|
|
foreach(curColType, colTypes)
|
|
{
|
|
Oid colType = lfirsto(curColType);
|
|
int32 colTypmod = colTypmods[colindex++];
|
|
TargetEntry *reftle = (TargetEntry *) lfirst(refnames_tlist);
|
|
|
|
Assert(reftle->resdom->resno == resno);
|
|
Assert(!reftle->resdom->resjunk);
|
|
expr = (Node *) makeVar(0,
|
|
resno,
|
|
colType,
|
|
colTypmod,
|
|
0);
|
|
resdom = makeResdom((AttrNumber) resno++,
|
|
colType,
|
|
colTypmod,
|
|
pstrdup(reftle->resdom->resname),
|
|
false);
|
|
tlist = lappend(tlist, makeTargetEntry(resdom, (Expr *) expr));
|
|
refnames_tlist = lnext(refnames_tlist);
|
|
}
|
|
|
|
if (flag)
|
|
{
|
|
/* Add a resjunk flag column */
|
|
resdom = makeResdom((AttrNumber) resno++,
|
|
INT4OID,
|
|
-1,
|
|
pstrdup("flag"),
|
|
true);
|
|
/* flag value is shown as copied up from subplan */
|
|
expr = (Node *) makeVar(0,
|
|
resdom->resno,
|
|
INT4OID,
|
|
-1,
|
|
0);
|
|
tlist = lappend(tlist, makeTargetEntry(resdom, (Expr *) expr));
|
|
}
|
|
|
|
pfree(colTypmods);
|
|
|
|
return tlist;
|
|
}
|
|
|
|
/*
|
|
* Does tlist have same datatypes as requested colTypes?
|
|
*
|
|
* Resjunk columns are ignored if junkOK is true; otherwise presence of
|
|
* a resjunk column will always cause a 'false' result.
|
|
*/
|
|
static bool
|
|
tlist_same_datatypes(List *tlist, List *colTypes, bool junkOK)
|
|
{
|
|
List *i;
|
|
|
|
foreach(i, tlist)
|
|
{
|
|
TargetEntry *tle = (TargetEntry *) lfirst(i);
|
|
|
|
if (tle->resdom->resjunk)
|
|
{
|
|
if (!junkOK)
|
|
return false;
|
|
}
|
|
else
|
|
{
|
|
if (colTypes == NIL)
|
|
return false;
|
|
if (tle->resdom->restype != lfirsto(colTypes))
|
|
return false;
|
|
colTypes = lnext(colTypes);
|
|
}
|
|
}
|
|
if (colTypes != NIL)
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
|
|
/*
|
|
* find_all_inheritors -
|
|
* Returns a list of relation OIDs including the given rel plus
|
|
* all relations that inherit from it, directly or indirectly.
|
|
*/
|
|
List *
|
|
find_all_inheritors(Oid parentrel)
|
|
{
|
|
List *examined_relids = NIL;
|
|
List *unexamined_relids = makeListo1(parentrel);
|
|
|
|
/*
|
|
* While the queue of unexamined relids is nonempty, remove the first
|
|
* element, mark it examined, and find its direct descendants. NB:
|
|
* cannot use foreach(), since we modify the queue inside loop.
|
|
*/
|
|
while (unexamined_relids != NIL)
|
|
{
|
|
Oid currentrel = lfirsto(unexamined_relids);
|
|
List *currentchildren;
|
|
|
|
unexamined_relids = lnext(unexamined_relids);
|
|
examined_relids = lappendo(examined_relids, currentrel);
|
|
currentchildren = find_inheritance_children(currentrel);
|
|
|
|
/*
|
|
* Add to the queue only those children not already seen. This
|
|
* avoids making duplicate entries in case of multiple inheritance
|
|
* paths from the same parent. (It'll also keep us from getting
|
|
* into an infinite loop, though theoretically there can't be any
|
|
* cycles in the inheritance graph anyway.)
|
|
*/
|
|
currentchildren = set_differenceo(currentchildren, examined_relids);
|
|
unexamined_relids = set_uniono(unexamined_relids, currentchildren);
|
|
}
|
|
|
|
return examined_relids;
|
|
}
|
|
|
|
/*
|
|
* expand_inherited_rtentry
|
|
* Check whether a rangetable entry represents an inheritance set.
|
|
* If so, add entries for all the child tables to the query's
|
|
* rangetable, and return an integer list of RT indexes for the
|
|
* whole inheritance set (parent and children).
|
|
* If not, return NIL.
|
|
*
|
|
* When dup_parent is false, the initially given RT index is part of the
|
|
* returned list (if any). When dup_parent is true, the given RT index
|
|
* is *not* in the returned list; a duplicate RTE will be made for the
|
|
* parent table.
|
|
*
|
|
* A childless table is never considered to be an inheritance set; therefore
|
|
* the result will never be a one-element list. It'll be either empty
|
|
* or have two or more elements.
|
|
*
|
|
* NOTE: after this routine executes, the specified RTE will always have
|
|
* its inh flag cleared, whether or not there were any children. This
|
|
* ensures we won't expand the same RTE twice, which would otherwise occur
|
|
* for the case of an inherited UPDATE/DELETE target relation.
|
|
*
|
|
* XXX probably should convert the result type to Relids?
|
|
*/
|
|
List *
|
|
expand_inherited_rtentry(Query *parse, Index rti, bool dup_parent)
|
|
{
|
|
RangeTblEntry *rte = rt_fetch(rti, parse->rtable);
|
|
Oid parentOID;
|
|
List *inhOIDs;
|
|
List *inhRTIs;
|
|
List *l;
|
|
|
|
/* Does RT entry allow inheritance? */
|
|
if (!rte->inh)
|
|
return NIL;
|
|
Assert(rte->rtekind == RTE_RELATION);
|
|
/* Always clear the parent's inh flag, see above comments */
|
|
rte->inh = false;
|
|
/* Fast path for common case of childless table */
|
|
parentOID = rte->relid;
|
|
if (!has_subclass(parentOID))
|
|
return NIL;
|
|
/* Scan for all members of inheritance set */
|
|
inhOIDs = find_all_inheritors(parentOID);
|
|
|
|
/*
|
|
* Check that there's at least one descendant, else treat as no-child
|
|
* case. This could happen despite above has_subclass() check, if
|
|
* table once had a child but no longer does.
|
|
*/
|
|
if (lnext(inhOIDs) == NIL)
|
|
return NIL;
|
|
/* OK, it's an inheritance set; expand it */
|
|
if (dup_parent)
|
|
inhRTIs = NIL;
|
|
else
|
|
inhRTIs = makeListi1(rti); /* include original RTE in result */
|
|
|
|
foreach(l, inhOIDs)
|
|
{
|
|
Oid childOID = lfirsto(l);
|
|
RangeTblEntry *childrte;
|
|
Index childRTindex;
|
|
|
|
/* parent will be in the list too; skip it if not dup requested */
|
|
if (childOID == parentOID && !dup_parent)
|
|
continue;
|
|
|
|
/*
|
|
* Build an RTE for the child, and attach to query's rangetable
|
|
* list. We copy most fields of the parent's RTE, but replace
|
|
* relation real name and OID. Note that inh will be false at
|
|
* this point.
|
|
*/
|
|
childrte = copyObject(rte);
|
|
childrte->relid = childOID;
|
|
parse->rtable = lappend(parse->rtable, childrte);
|
|
childRTindex = length(parse->rtable);
|
|
|
|
inhRTIs = lappendi(inhRTIs, childRTindex);
|
|
}
|
|
|
|
return inhRTIs;
|
|
}
|
|
|
|
/*
|
|
* adjust_inherited_attrs
|
|
* Copy the specified query or expression and translate Vars referring
|
|
* to old_rt_index to refer to new_rt_index.
|
|
*
|
|
* We also adjust varattno to match the new table by column name, rather
|
|
* than column number. This hack makes it possible for child tables to have
|
|
* different column positions for the "same" attribute as a parent, which
|
|
* helps ALTER TABLE ADD COLUMN. Unfortunately this isn't nearly enough to
|
|
* make it work transparently; there are other places where things fall down
|
|
* if children and parents don't have the same column numbers for inherited
|
|
* attributes. It'd be better to rip this code out and fix ALTER TABLE...
|
|
*/
|
|
Node *
|
|
adjust_inherited_attrs(Node *node,
|
|
Index old_rt_index, Oid old_relid,
|
|
Index new_rt_index, Oid new_relid)
|
|
{
|
|
adjust_inherited_attrs_context context;
|
|
|
|
/* Handle simple case simply... */
|
|
if (old_rt_index == new_rt_index)
|
|
{
|
|
Assert(old_relid == new_relid);
|
|
return copyObject(node);
|
|
}
|
|
|
|
context.old_rt_index = old_rt_index;
|
|
context.new_rt_index = new_rt_index;
|
|
context.old_relid = old_relid;
|
|
context.new_relid = new_relid;
|
|
|
|
/*
|
|
* Must be prepared to start with a Query or a bare expression tree.
|
|
*/
|
|
if (node && IsA(node, Query))
|
|
{
|
|
Query *newnode;
|
|
|
|
newnode = query_tree_mutator((Query *) node,
|
|
adjust_inherited_attrs_mutator,
|
|
(void *) &context,
|
|
QTW_IGNORE_RT_SUBQUERIES);
|
|
if (newnode->resultRelation == old_rt_index)
|
|
{
|
|
newnode->resultRelation = new_rt_index;
|
|
/* Fix tlist resnos too, if it's inherited UPDATE */
|
|
if (newnode->commandType == CMD_UPDATE)
|
|
newnode->targetList =
|
|
adjust_inherited_tlist(newnode->targetList,
|
|
new_relid);
|
|
}
|
|
return (Node *) newnode;
|
|
}
|
|
else
|
|
return adjust_inherited_attrs_mutator(node, &context);
|
|
}
|
|
|
|
static Node *
|
|
adjust_inherited_attrs_mutator(Node *node,
|
|
adjust_inherited_attrs_context *context)
|
|
{
|
|
if (node == NULL)
|
|
return NULL;
|
|
if (IsA(node, Var))
|
|
{
|
|
Var *var = (Var *) copyObject(node);
|
|
|
|
if (var->varlevelsup == 0 &&
|
|
var->varno == context->old_rt_index)
|
|
{
|
|
var->varno = context->new_rt_index;
|
|
if (var->varattno > 0)
|
|
{
|
|
char *attname = get_attname(context->old_relid,
|
|
var->varattno);
|
|
|
|
var->varattno = get_attnum(context->new_relid, attname);
|
|
if (var->varattno == InvalidAttrNumber)
|
|
elog(ERROR, "Relation \"%s\" has no column \"%s\"",
|
|
get_rel_name(context->new_relid), attname);
|
|
pfree(attname);
|
|
}
|
|
}
|
|
return (Node *) var;
|
|
}
|
|
if (IsA(node, RangeTblRef))
|
|
{
|
|
RangeTblRef *rtr = (RangeTblRef *) copyObject(node);
|
|
|
|
if (rtr->rtindex == context->old_rt_index)
|
|
rtr->rtindex = context->new_rt_index;
|
|
return (Node *) rtr;
|
|
}
|
|
if (IsA(node, JoinExpr))
|
|
{
|
|
/* Copy the JoinExpr node with correct mutation of subnodes */
|
|
JoinExpr *j;
|
|
|
|
j = (JoinExpr *) expression_tree_mutator(node,
|
|
adjust_inherited_attrs_mutator,
|
|
(void *) context);
|
|
/* now fix JoinExpr's rtindex */
|
|
if (j->rtindex == context->old_rt_index)
|
|
j->rtindex = context->new_rt_index;
|
|
return (Node *) j;
|
|
}
|
|
if (IsA(node, InClauseInfo))
|
|
{
|
|
/* Copy the InClauseInfo node with correct mutation of subnodes */
|
|
InClauseInfo *ininfo;
|
|
|
|
ininfo = (InClauseInfo *) expression_tree_mutator(node,
|
|
adjust_inherited_attrs_mutator,
|
|
(void *) context);
|
|
/* now fix InClauseInfo's relid sets */
|
|
ininfo->lefthand = adjust_relid_set(ininfo->lefthand,
|
|
context->old_rt_index,
|
|
context->new_rt_index);
|
|
ininfo->righthand = adjust_relid_set(ininfo->righthand,
|
|
context->old_rt_index,
|
|
context->new_rt_index);
|
|
return (Node *) ininfo;
|
|
}
|
|
|
|
/*
|
|
* We have to process RestrictInfo nodes specially.
|
|
*/
|
|
if (IsA(node, RestrictInfo))
|
|
{
|
|
RestrictInfo *oldinfo = (RestrictInfo *) node;
|
|
RestrictInfo *newinfo = makeNode(RestrictInfo);
|
|
|
|
/* Copy all flat-copiable fields */
|
|
memcpy(newinfo, oldinfo, sizeof(RestrictInfo));
|
|
|
|
/* Recursively fix the clause itself */
|
|
newinfo->clause = (Expr *)
|
|
adjust_inherited_attrs_mutator((Node *) oldinfo->clause, context);
|
|
|
|
/*
|
|
* We do NOT want to copy the original subclauseindices list, since
|
|
* the new rel will have different indices. The list will be rebuilt
|
|
* when needed during later planning.
|
|
*/
|
|
newinfo->subclauseindices = NIL;
|
|
|
|
/*
|
|
* Adjust left/right relid sets too.
|
|
*/
|
|
newinfo->left_relids = adjust_relid_set(oldinfo->left_relids,
|
|
context->old_rt_index,
|
|
context->new_rt_index);
|
|
newinfo->right_relids = adjust_relid_set(oldinfo->right_relids,
|
|
context->old_rt_index,
|
|
context->new_rt_index);
|
|
|
|
newinfo->eval_cost.startup = -1; /* reset these too */
|
|
newinfo->this_selec = -1;
|
|
newinfo->left_pathkey = NIL; /* and these */
|
|
newinfo->right_pathkey = NIL;
|
|
newinfo->left_mergescansel = -1;
|
|
newinfo->right_mergescansel = -1;
|
|
newinfo->left_bucketsize = -1;
|
|
newinfo->right_bucketsize = -1;
|
|
|
|
return (Node *) newinfo;
|
|
}
|
|
|
|
/*
|
|
* NOTE: we do not need to recurse into sublinks, because they should
|
|
* already have been converted to subplans before we see them.
|
|
*/
|
|
Assert(!IsA(node, SubLink));
|
|
Assert(!IsA(node, Query));
|
|
|
|
/*
|
|
* BUT: although we don't need to recurse into subplans, we do need to
|
|
* make sure that they are copied, not just referenced as
|
|
* expression_tree_mutator will do by default. Otherwise we'll have
|
|
* the same subplan node referenced from each arm of the inheritance
|
|
* APPEND plan, which will cause trouble in the executor. This is a
|
|
* kluge that should go away when we redesign querytrees.
|
|
*/
|
|
if (is_subplan(node))
|
|
{
|
|
SubPlan *subplan;
|
|
|
|
/* Copy the node and process subplan args */
|
|
node = expression_tree_mutator(node, adjust_inherited_attrs_mutator,
|
|
(void *) context);
|
|
/* Make sure we have separate copies of subplan and its rtable */
|
|
subplan = (SubPlan *) node;
|
|
subplan->plan = copyObject(subplan->plan);
|
|
subplan->rtable = copyObject(subplan->rtable);
|
|
return node;
|
|
}
|
|
|
|
return expression_tree_mutator(node, adjust_inherited_attrs_mutator,
|
|
(void *) context);
|
|
}
|
|
|
|
/*
|
|
* Substitute newrelid for oldrelid in a Relid set
|
|
*/
|
|
static Relids
|
|
adjust_relid_set(Relids relids, Index oldrelid, Index newrelid)
|
|
{
|
|
if (bms_is_member(oldrelid, relids))
|
|
{
|
|
/* Ensure we have a modifiable copy */
|
|
relids = bms_copy(relids);
|
|
/* Remove old, add new */
|
|
relids = bms_del_member(relids, oldrelid);
|
|
relids = bms_add_member(relids, newrelid);
|
|
}
|
|
return relids;
|
|
}
|
|
|
|
/*
|
|
* Adjust the targetlist entries of an inherited UPDATE operation
|
|
*
|
|
* The expressions have already been fixed, but we have to make sure that
|
|
* the target resnos match the child table (they may not, in the case of
|
|
* a column that was added after-the-fact by ALTER TABLE). In some cases
|
|
* this can force us to re-order the tlist to preserve resno ordering.
|
|
* (We do all this work in special cases so that preptlist.c is fast for
|
|
* the typical case.)
|
|
*
|
|
* The given tlist has already been through expression_tree_mutator;
|
|
* therefore the TargetEntry nodes are fresh copies that it's okay to
|
|
* scribble on. But the Resdom nodes have not been copied; make new ones
|
|
* if we need to change them!
|
|
*
|
|
* Note that this is not needed for INSERT because INSERT isn't inheritable.
|
|
*/
|
|
static List *
|
|
adjust_inherited_tlist(List *tlist, Oid new_relid)
|
|
{
|
|
bool changed_it = false;
|
|
List *tl;
|
|
List *new_tlist;
|
|
bool more;
|
|
int attrno;
|
|
|
|
/* Scan tlist and update resnos to match attnums of new_relid */
|
|
foreach(tl, tlist)
|
|
{
|
|
TargetEntry *tle = (TargetEntry *) lfirst(tl);
|
|
Resdom *resdom = tle->resdom;
|
|
|
|
if (resdom->resjunk)
|
|
continue; /* ignore junk items */
|
|
|
|
attrno = get_attnum(new_relid, resdom->resname);
|
|
if (attrno == InvalidAttrNumber)
|
|
elog(ERROR, "Relation \"%s\" has no column \"%s\"",
|
|
get_rel_name(new_relid), resdom->resname);
|
|
if (resdom->resno != attrno)
|
|
{
|
|
resdom = (Resdom *) copyObject((Node *) resdom);
|
|
resdom->resno = attrno;
|
|
tle->resdom = resdom;
|
|
changed_it = true;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If we changed anything, re-sort the tlist by resno, and make sure
|
|
* resjunk entries have resnos above the last real resno. The sort
|
|
* algorithm is a bit stupid, but for such a seldom-taken path, small
|
|
* is probably better than fast.
|
|
*/
|
|
if (!changed_it)
|
|
return tlist;
|
|
|
|
new_tlist = NIL;
|
|
more = true;
|
|
for (attrno = 1; more; attrno++)
|
|
{
|
|
more = false;
|
|
foreach(tl, tlist)
|
|
{
|
|
TargetEntry *tle = (TargetEntry *) lfirst(tl);
|
|
Resdom *resdom = tle->resdom;
|
|
|
|
if (resdom->resjunk)
|
|
continue; /* ignore junk items */
|
|
|
|
if (resdom->resno == attrno)
|
|
new_tlist = lappend(new_tlist, tle);
|
|
else if (resdom->resno > attrno)
|
|
more = true;
|
|
}
|
|
}
|
|
|
|
foreach(tl, tlist)
|
|
{
|
|
TargetEntry *tle = (TargetEntry *) lfirst(tl);
|
|
Resdom *resdom = tle->resdom;
|
|
|
|
if (!resdom->resjunk)
|
|
continue; /* here, ignore non-junk items */
|
|
|
|
if (resdom->resno != attrno)
|
|
{
|
|
resdom = (Resdom *) copyObject((Node *) resdom);
|
|
resdom->resno = attrno;
|
|
tle->resdom = resdom;
|
|
}
|
|
new_tlist = lappend(new_tlist, tle);
|
|
attrno++;
|
|
}
|
|
|
|
return new_tlist;
|
|
}
|